Diaphragm operated vacuum control system



May 15, 1956 A. E. BROUGHTON 2,745,322

DIAPHRAGM OPERATED VACUUM CONTROL SYSTEM May 15, 1955 A. E. BROUGHTONDIPHRAGM OPERATED VACUUM CONTROL SYSTEM 2 Sheets-Sheet 2 FiledJan. 14,1954 United States Patent O DIAPHRAGM OPERATED VACUUM CONTROL SYSTEMArthur E. Broughton, Glens Falls, N. Y.

Application January 14, 1954, Serial No. 404,079

7 Claims. (Ci. 92-51) This invention relates to a vacuum control systemin combination with the suction head of a paper making machine.

The system disclosed and claimed herein is an improvement on thecombination disclosed in my prior patents, No. 1,962,477 granted June12, 1934, and No. 2,147,877 granted February 21, 1939, and is acontinuation in part of my co-pending application, Seriall No. 66,007,led December 18, 1948, now abandoned and entitled Vacuum Contro as wellas being a division thereof with respect to the subject matter disclosedand claimed therein relating to the combination of the suction head andthe diaphragm actuated suction control valve.

While my prior systems worked reasonably well and were a greatimprovement over any apparatus previously known, I found that thecorrosive action of the paper making solutions produced considerablecorrosion between the piston and surrounding cylinder wall whichfrequently caused sticking of the controller piston and rendered thesame inoperative. Also chattering of control valves for such systems hasalways been a serious problem.

It is an object of my present invention to provide a system foraccurately and constantly controlling and maintaining a predeterminedvacuum in a suction head of a paper making machine and particularlyconstructed to prevent corrosive action of the paper making solutions onthe actuating elements thereof and also designed to substantiallyeliminate chattering of the control valve mechanism. n

. It is another object to provide a highly ecient and extremely accuratecontrol system including in the combination thereof a diaphragm actuated'vacuum control valve which entirely eliminates any ysliding actionbetween the actuator elements of the controller and thereby preventingany harmful effect of the'corrosive solutions and vapors on theeliicient operation of the vacuum controller system.A

It is still another object to provide a new and highly eicientcombination including a suction head for a paper making machine, asource of negative pressure communicating with said head to draw air andwater through said 'suction head with means for separating said'air andwater, and including a control valve controlling the degree of suctionproduced in said head :and having a highly trol of a suction head usedin a paper making machine and provided lwith a fresh air ventcommunicating with 1 the high pressure side or" the valve actuator tomaterially reduce'the concentration of corrosive vapors inthe air drawntherein from the suction head.

2,745,322 Patented May 15, 195.6

These and other objects and advantages of this invention will more fullyappear from the following description made in connection with theaccompanying drawings wherein like reference characters refer to thesame or similar parts throughout the several views, and in which:

Fig. 1 is a front elevational View showing my new combination includingportions of a fourdrinier paper making machine; v

Fig. 2 is a vertical sectional view showing the control valve andactuator therefor which are used in my new combination;

Fig. 3 is a central vertical sectional view taken longitudinally througha at box of a paper making machine and showing certain elements of mynew combination in side elevation; p

Fig. 4 is a side elevational view of the controller and valve housingused in my new combination; and

Fig. 5 is a fragmentary vertical sectional view taken centrally throughthe valve housing substantially along the line 5 5 of Fig. 2. y y

As best shown in Fig. 1 of the accompanying drawing, l provide a vacuumsystem for removing themoisture from a layer ofpaper pulp in the processof'm'anufactun'ng paper. A conventional couchpump 1i) pro vides a sourceof suction for the paper making machine and communicates directly withan otherwise closed couch roll 11 around which the Fourdrinier wire 12passes at the delivery end thereof. The layer of paper pulp from which alarge percentage of the moisture has been removed through the wire 12forms a paper web 134 and leaves the wire 12 above the couch roll 11 andpasses around a guiding roll 14 and extends to a supporting felt 15 andis carried therefrom to the dryers in the usual manner. p

A branch suction line 16 is connected with themain suction conduitextending from the couch pump 10 to the couch roll 11, and a handoperated valve 17 controls the degree of vacuum supplied through suctionline 16 to the ilat boxes 18 which constitute the suction heads to becontrolled. The suction line 16 forms a header 34 from which individualconduits afford communication to the respective at boxes 18. A'controller` actuated valve 19 is provided for each flatbox 18 andcontrols the suction thereto through the upper portion of an upstandingreceiving conduit which forms air leg 20. AV

withdrawal kconduit 32 is connectedatV one end to the discharge end ofeach dat box 18 Tand is connected at 'its other end to a connector l 33through a exible con-"v A water leg 2,1, is connected at nector element32a. v its upper end with the T 33:l and is formed by the lower. portionof the upstanding receiving conduit to"whic h the air and Water fromeach flat box 18 is delivered. 4The lower end of the water leg 21 issealed as-by being submerged in the reservoir tank 22, the level in saidtank being maintained by a pump 23 which'is renderedinoperative unlessthe vent line 24 is submerged belvowthe.I T he4 pump, when operafH levelof the liquid in tank 22. tive, removesv liquid from said tankthrough.inlet;231I and delivers the white water received therethroughforsubsequent use in the manufacturing process. Since-the white watercontains a small percentage of paper pulp,` it

is desirable to avoid disposal thereof if possible.

A controller A is connected with each ofthe valves 19 for actuating thesame, and each controller has a lower 3 ber formed Within the twointerconnected casing sections 25V and'2'6 into a relief chamber 28 andan actuating chamber 29. Both chambers 28 and 29 are sealed ex cept-for' a 4singlev outlet, `the relief chamber 28 cornmuncates with theatmosphere through said outlet, a con- -duit 30, and ar relief header 31to which the conduit is connected Aand which. extends through thebuilding wall to. the outsidevatmosphere, as best shown in Fig. 1. Thispermits fresh outside air to be drawn into the upper charnber 28V whentheV valve-B is opened to produce negative pressure in said chamber andthus materially reducing the concentration of paper solution moistureinthe air within chambers Y28 and 29.

A. branch pipe 35 interconnects valve 19 with ythe Vsuction header 34,and a pressure regulating valve 36 is providedin said pipe 35. In the-form shown, this pressure regulating valve 36 consists in .one of mydiaphragm operated controller. units A, such as the units previouslyprovided herein, and a pressure-sensitive conduit 46affordscommunication between the control chamber of the controller unit36a for communication between the rcontrol chamber. of controller, A andthe header 34 at the desiredfpoint of control. Also, a communicationconduit 3617 aiords affords communication between the relief supplyheader 31 and the relief chamber disposed above the diaphragmandmaintained at atmospheric rpressure by; said conduits 36a and 31.; Thiscontrol unit 36 maintains a predetermined maximum limit on the vacuumsuppliedto said valve 19 and is of course adjustable to limit thepressure diiierential between the maximum vacuum supplied and thedesired vacuum to be main-V tained byV my control system. The valve 19controls the flow to the upper portion of air leg through a pipe 37 andagauge 38 may be providedrat the top of each of the air legs 20 toindicate the vacuum therein. A pres sure sensing communication conduit39 is connected'at one end to the outlet from control chamber 29 and atthe other end to the air leg 20 in spaced relation above the T 33. Thedistance between the connection of the conduit 39 and the T 33 issucient to prevent foam produced in the water leg 21 from rising intothe controller A .to thus further reduce contact between the corrosivemoisture and the controller parts.

An adjustable balancing spring 40 is, in the form shown, provided inchamber 29 to overcome the force exerted ondiaphragm- 27 by apredetermined adjustable suction which is controlled by valve 19 andcommunicated to chamber 29` by conduit- 39. The adjustable compressionspring 40 is seated at its upper end on the outer marginal portion 41aof a spring seat member 41 which is secured to the underside ofdiaphragm 27 in a manner to be described. The lower end of spring 40 is`seated on an adjustable spring seat 42 which is mounted on a yscrewstem 43 with an operating handle 44 connected therewith to adjustablyvary the compression in spring 40 and thereby vary the counterbalancingforce exerted by said spring on diaphragm27 which overcomes a predeptermined suction on said diaphragm produced by the suction in air leg20.`- An aperture is provided in the central portion ofvupper springseat 41 and the valve B controls vthe ow of air between chambers 28 and29 as has been tion of the diaphragmY interposed therebetween lin sealedrelation. It-s`houldbe notedthat the outer marginal por- Vtions ofthe-.rtwoseaty elements-41 and Y45 on thesidesV thereof adjacent thediaphragm- 27 diverge from the diaphragur 'to' provide smoothlycontoured' engagement ;por-Y tions ,for thev ,adjacent diaphragm:surfaces to* minimize' 4 the wear ,thereon ,during exing of thediaphragm. An elongated valve sleeve 46 is shiftably mounted through theopening in the two seat members 45 and 41 and diaphragm 27, and has asealing ange 46a around the upper portion thereof for sealed engagementwith the portion of the valve seat 45 surrounding the openingtherethrough, a sealing gasket 46b being provided between said ilangeland said seat. A lightly tensionedreliet` valve closure spring 47 Visinterposed between the seat member 41 and a top collar 47a connected tothe lower portion of the elongated sleeve 46 and resiliently resistsseparation of flange 46a'and valve seat 45. The construction of valve19` is generally similar to that disclosed in my prior patent, No.2,147,877, and is a double poppet valve with an upstanding guiding stem19a and a depending actuating stem 48 slidably mounted in a suitableguideway 26a formed in the upper casing member 2 6. The lower endofxstem .48 is securely anchored to the upper portion of valve sleeve 46as by being threadably connected therewith and having a locking pin 48aextending wardly; spaced relation below the valve ange 46a: As'l thediaphragm 27 is exed' by variations inthe relative pressures betweenchambers 28v and 29,V the valve stem 48 is actuated upwardly or'thevalve seat 45 is shifted downwardly away from relief valve flange 46awhen' control valve. 19 Vis in seated position.

The following is a description of the operation of my new system'asdisclosed herein. The resilient compression is initially adjusted incontrol spring 40 by turning operatinghandle 44 .to resist andcounterbalance a `predetermined suction in air leg`20. Unless at leastthis predeterminedsuction is produced in air leg 20 and the -flat box 18connected therewith, the spring 40 will of course push diaphragm 27upwardly tovopen control valve Y19'.-

nitude to overcome the force .exerted by spring 40, saidV diaphragm,willV immediately pull the valve 19 down'-l Obviously, duringoperation, variations in the; degree of vopening of valve v19 willwardly into closed position.

be only momentary to maintain a precisely predeter- V mined suctoninthecontrolled dat boX- 18. TheA pressure inl ,chamber 29 will, ofcourse,always be the same.

as that i-n air vleg 20 which communicates `therewith through Aconduit39, and the pressure in chamber 28 dis'-V posed-above diaphragm 27 isconstantly maintainedv at'- atmospheric by relief supply conduit 30which is connected indirect communication `with the outside air throughheader 31. a predetermined limit, the diaphragm 29 is pulled downwardlyto further' compress spring 40 if the Ycontrol valve.

19 has beenshifted into closed seated position andrelief air atatmospheric pressure is drawn intochamber 29andV airleg1201throu'ghconduit 30 and relief valve B. The relief Valve B,V by the progressivelydownwardly posi` tion'ed apertures 46c, initially provides a relativelysmall area,ofcommunicationbetweenv chambers 28 and 29, but

progressively increases this area as diaphragm 27 is pulled toprogressively increase the shifting movement of valvel seat 45vdownwardly along sleeve 46. I have found vthat the'imaximumdifferentialbetween the vacuum supplied through condu'ity16 and the ultimatedesiredv vacuum" to lbe maintained in highest vacuum carried in the-fiatboxes18 must not be more than 4 inches of mercuryin' excess of ,-the;highest vacuum beingdrawn" in the'vtiat'v boxes itorpre'vent'chatteringof the. valve 19. e Irrotlier words, ,a .greater diierential thanV thiscritical maximum' limit-,causev s'uddent increasesk in the suction intlat box 18 which will immediately snap control valve'v If the suctioninair leg 20'exceeds closed rather than merely gradually or partiallyclosing the same. Obviously as soon as said valve is snapped shut thecontroller will again call for increased suction and open the same tocause thedisagreeable and destructive chattering. However,A if byadjustment of regulation valve 36 this pressure differential ismaintained at less than 4 lbs. per sq. inch between the desired pressureon the flat box 18 and the maximum vacuum being supplied to valve 19 byconduit 16, the opening valve 19 will not cause a sudden increase in thesuction in at box 18 but will cause only a gradual increase in saidsuction which will not result in said valve being immediately snappedshut and thereafter immediately snapped open and thus prevent thechattering described above. This chattering as has been previouslydescribed can also be caused if the relief valve initially affords arelatively large area of communication between chamber 28 and chamber 29when the same is initially opened to cause said relief valve to besnapped shut and the control valve to be opened, but this'issubstantially eliminated in my present combination by the relief valve Baifording only a limiting area of communication when initially opened.

It will be seen that I have provided a highly ecient combination ofelements designed to produce an extremely durable and highly accuratesystem for precisely controlling a desired vacuum in a suction head suchas the at box 18 by eliminating the deleterious effect of the corrosivesolution used in paper making processes and which will substantiallyeliminate all chattering of the controller by eliminating sudden changesin the suction being produced in the at box 18. All of the advantagespresent in my previously identied patented inventions are, of course,also present in the instant invention as well as the specific advantagesset forth herein.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the parts withoutdeparting from the scope of this invention which, generally stated,consists in the matter shown and described herein and set forth in theappended claims.

What I claim is:

l. In a paper making machine, a system for controlling the vacuum in asuction head comprising a suction head positioned to remove Water froman overlying layer of diluted paper pulp, a withdrawal conduitcommunicating with said suction head to permit the air and water drawninto said suction head to be removed therefrom, a hollow upstandingreceiving member communicating with said withdrawal conduit and having adownwardly extended drainage leg with the lower end thereof vacuumsealed and through which water removed from said suction head is adaptedto ow and having an upwardly extending air withdrawal leg, a vacuumcontrol valve controlling the vacuum supplied to said air leg, adiaphragm controller operatively associated with said control valveincluding a chamber communicating with said suction head, a diaphragmworking in said chamber, and a relief valve aiording communicationbetween said chamber and air under at least atmospheric pressure andoperatively connected with said diaphragm for increasing the pressure insaid chamber when the vacuum therein reaches a predetermined maximumlimit.

2. In a paper making machine, a system for controlling the vacuum in asuction head comprising a suction head to remove water from an overlyinglayer of diluted paper pulp, a withdrawal conduit communicating withsaid suction head to permit the air and water drawn into said head to beremoved therefrom, a hollow upstanding receiving member communicatingwith said withdrawal conduit and having a downwardly extending drainageleg with the lower end thereof Water-sealed and through which waterremoved from said suction head is adapted to ow and having an upwardlyextending air Withdrawal leg, a vacuum control valve controlling thevacuum supplied to said leg, pressure sensitive means communicating withsaid suction head and operatively associated with said valve for openingand closing the same in response to variations in the suction in saidhead, and a regulating valve limiting the maximum vacuum supplied tosaid vacuum control valve to positively limit the diiferential betweenthe vacuum maintained in said suction head and the vacuum supplied tosaid control valve.

3. The combination set forth in claim 2, and said control meansincluding a relief valve operatively associated with said control meansand affording communication between said suction head and at leastatmospheric pressure when opened by a predetermined maximum suctionproduced in said head, said relief valve being constructed t0 permitonly restricted pressure release upon initial opening thereof.

4. ln a paper making machine, a system for controlling the vacuum in asuction head comprising a suction head positioned to remove water froman overlying layer of diluted paper pulp, a withdrawal conduitcommunicating with said suction head to permit the air and water drawninto said suction head to be removed therefrom, means connected withsaid suction head withdrawal conduit for supplying suction thereto, acontrol valve mounted in said suction supply means for controlling thesuction supplied therethrough, means deiining a control chambercommunicating with said suction head, a control daphragm working in saidchamber and operatively associated with said valve for opening andclosing the same in response to variations in the suction produced insaid suction head, and a relief valve operatively associated with saiddiaphragm for supplying air under at least atmospheric pressure to saidsuction head whenever the suction therein reaches a predeterminedmaximum limit.

5. The structure set forth in claim 4, and a regulating valve limitingthe maximum vacuum supplied to said control valve to maintain thepressure diiferential between the supply vacuum and the controlledvacuum below a predetermined maximum limit to prevent suddenfluctuations in the vacuum in said suction head.

6. In a paper making machine, a system for controlling the vacuum in asuction head comprising a suction head positioned to remove water froman overlying layer of diluted paper pulp, means for supplying vacuum tosaid suction head, a vacuum control valve connected in said vacuumsupply means for controlling the 'degree of suction supplied to saidhead, a controller casing with a flexible, pressure-responsive diaphragminterposed therein to divide the interior thereof` into a controlchamber and a relief chamber, means affording communication between saidcontrol chamber and the suction head, relief means aifordingcommunication between the other chamber and a source of fresh air remotefrom the suction head, under at least atmospheric pressure free from thecorrosive vapors produced by the paper making solutions, said diaphragmhaving a communication opening formed therethrough, a relief valvemounted in said opening to control the air flow therethrough, andconnection means interconnecting said vacuum control valve and saiddiaphragm to open and close said valve in response to variations inpressure in said control chamber, said diaphragm being operativelyassociated with the opening and closing of said relief valve to affordcommunication between the relief chamber and the control chamber whenthe vacuum in said relief chamber and said suction head reaches apredetermined maximum limit.

7. In a paper making machine, a system for controlling the vacuum in asuction head comprising a suction head for removing water from anoverlying layer of diluted paper pulp, a withdrawal conduitcommunicating with said suction head to permit the air and water drawninto said head to be removed therefrom, a hollow upstanding receivingmember communicating with said withdrawal conduit and having adownwardly extending drainage leg with the lower end thereof watersealed and through which 7 water reroved from said suction legY i sadapted teow, Saidvdainage; 19e inc'hidng an upwardly extending airwithdrawal leg7V a lsuction supply :onduit lnrlrlectedl with the upper'portion off said air withdrawal leg, a pair of vacnum controlva1vesrespectively controlling lthe x'am supplied to said air legandthrougph said suction Ysupply conduit', a pair of pressure-sensitivecontrollersone comf munieating with said suction head and the othercommunicating. with said supply conduit and respectively operativelyassociated with said valves for respectively opening and closing thesame yin response to variations in the vacuum in said head and` saidconduit, and the cony troller associated with the valve in said conduitbeing constructed and set to constantly maintain a vacuum in excess ofthe vacuum to be maintained by the controller communicating with saidsuction head but positively limiting 8 the diterential Between Ythe vatwo cont-rollers;v

num `maintained by said l References Cited in the 'tile of thispatent 5UNITED STATES PATENTS 1,962,477 Broughton juney 12, 1934 1,969,546Bfughti 4 -V--Ag- 7,'1934 2,147,877 B'rpngufga -V, Fee. 21, 1939 1oREIGN-PATENTS 507,797 Great Britain Y June 2'1, 1939 OTHER REFERENCESPaper Industry ,and-'Paper World, January 1942, pages 15 998-4000.`(Copy in Division 67;)`

